It's been denounced as trickle-down economics, but at least since the late great Ronald Reagan's time, it's worked again and again.

First pour-down economics re-ignited the moribund economy that the hapless Jimmy Carter left the country when he departed the White House at the beginning of the 1980s to make way for the Great Communicator.

Presidential leadership can make all the difference first to the country's spirit, then its economy. Al Smith may have inspired the phrase the Happy Warrior, but it was Ronald Reagan who embodied it, just as Franklin Roosevelt had done in an earlier time.

Great presidents make a great difference.

They don't just lift the economy, but the whole nation's image of itself. Their eloquence is contagious, their pessimism all too tangible. So that when Franklin D. Roosevelt told the nation there was nothing to fear but fear itself, Americans in general strode forward confidently into a future that hadn't seemed as promising since the Roaring Twenties.

When Herbert Hoover sat glum and forbidding next to Franklin Roosevelt on his way to the latter's inauguration as president of the United States, he sent a sad signal to all those watching.

What kind of signal does the current president of the United States send its people? Is it a message mainly about himself rather than America's prospects? His self-infatuation is self-evident, but does it seek to empower only himself rather than the nation?

Our current president doesn't so much speak as tweet. He's a puzzlement. He definitely has the courage of his convictions, for he can stun the world when he tosses aside half a century or more of mealy-mouthed neutrality between right and wrong mislabeled as the Mideast Peace Process. Other presidents have promised to recognize Jerusalem as Israel's capital; he's doing so. And enraging those who would let loose the dogs of war throughout that part of the world. Yet the president forges ahead for no better reason than it's the right thing to do.

So it was with this president's tax bill. He was determined to rewrite the country's tax code despite all the doomsayers who warn that (a) it can't be done, (b) it shouldn't be done, (c) it won't be done and (d) all of the above. Readers can decide for themselves whether he has been brave or just foolhardy as he goes where few presidents have gone before.

The improbable thought occurs that our president believes not only in himself but in his own policies. Whom the gods would destroy, it has been well said, they put in charge of the Mideast peace process. Not since Harry Truman, whose self-effacing manner was quite the opposite of Mr. Trump's, has this country had a president so full of surprises. And some of them, it seems, may come as a surprise to the president himself.

The only thing for sure about this presidency may be that nothing about it is for sure.